Portable computers, such as Tablet PCs, laptops, PDA and Pocket PCs, have a number of challenging design issues. On the one hand, it is desirable that they should be light weight and easily carried and be easy to use. On the other hand, it is desirable they should have a long battery life, be powerful and provide a large display. These potentially conflicting design guidelines make it difficult to produce the ideal portable computer.
To minimize weight and space, one method has been to use a soft keyboard on the display for data entry. One method of providing a soft keyboard is to provide a display with a touch sensitive feature. A portion of the display, which may be a fraction ranging from 1 to 1/N where N is a positive integer, may be configured to display symbols, such as character of an alphabet, on soft keys in an arrangement that resembles a keyboard. By pressing on the appropriate place on the display, the symbol may be selected. By repeatedly selecting symbols, an individual may enter data in a known manner.
As can be appreciated, however, there is a limited amount of space available on the display of a portable device. The available space is further reduced if a portion of the display is to be used to display the selections of the user. In addition, reducing the size of symbols below a certain point is impracticable due to the difficult in visually distinguishing the difference in the symbols. Therefore, it can be difficult to display all the symbols that might be otherwise desirable to be displayed. This problem is further acerbated with certain languages that include symbols that may or may not include an accent.
One solution has been to provide modifier keys such as the shift key. By selecting the appropriate modifier key, the choices available for each soft key can change. However, this requires addition selections. The use of a modifier key on a regular hard keyboard is typically not an issue because both hands can be used simultaneously. However, a soft keyboard typically is operated by using the same finger or pointing device to select subsequent soft keys. Thus, requiring the user to first select a modifier key and then select the desired soft key can undesirably decrease the speed of data entry.